Change-speed transmission



June if?, 19?'73Y 'l G. J. RACKHNM v ,CHANGE SPEED TRANSMISSION Filed sept. 24g, was. zxspwsgxlwet v1 l 'l l June 7, 1927.-

G. J. RAclHAM 1'631338 CHANGE SPEED TRANSMISSION I Filed Sept. 2.4. 1923 2 Shoots-Sheet 2 la 15.9 [lll/-"IIIMIl////lllllll'l'," j@ H v ""0", if' i f A e L r "Y 9 l l 1+ IMA ff 145 di erentspeed combinations.

Patented i J une 7,1927..

UNITED; STATES v $531338 PATENT OFFICE.

GEORGE; RCKIIAII, ONCHICAGO, ILLINOIS, AssIGNOR rro YELLOW COACH vMANU-.,-

.FAC'IURINC CO., OF CHICAGO, ILLINOIS, A CORPORATION Or ILLINOIS.

' NCBLANen-srnnn TRANSMISSION.

- Application medseptember 24,1923. Serial No. eeasasj f This` invention has to do with certain improvements in lchange speed transmissions for' automobiles, `motor vehicles, and like uses. One of the objects offthe present invention is to .provide al change Ispeed transmission having provision for a pluralityl of speeds forward, together with a reversing position, one of the forward speed'positions, i0 preferably Ythe first or lowest speed, ibeing established' by the use of gears, and the other forward. speeds being established by the use of chains and sprockets. 4The use;

of chains and sprockets for certain ofthe Speed reductions will .present the advantage that a very quiet and smooth running'change speed arrangement is provided, since use may be made of so called silent chains or similar constructions.

In connection with the use of a gear drive for the first forward speed, together. with chainI drives for the other forward speeds and gear drives for reverse, I would also point Out that it be Omes possible to eliminate the use of an int rmediate or jack shaft during the reverse ge r drive, since a direct meshing of the gear and pinion on the transmission shaft and lay shaft, respectively will 4give a reverse drive as compared to the use ,30 of a chain connection between these shafts. In connection with all of the foregoing, a further Objectis to provide a' very simple -and compact construction', by the use of.

which it becomes possible to lsecure four speeds forward and one speed reverse, one of the' forward speeds and the reverse drive being attained by the use'of 'gears,:and two of the higher forward speeds being attained by the use of chain .drlvesjthe other `forward speed being direct drive.l

A' further. feature in this connection is to provide an arrangement whereby the various artsare sub]ected tovery simple and `re ar movements in passing through .the

Furtherob'ects and uses of the invention will appear rom a detailed description of the same, which consists in the features of p. construction and combinations of parts hereinafter described and claimed.

' In the drawings:

1 Figure-1 shows/a plan 'Orhorizontal cen- -tralsection through atran'smission embodyi'ng the featuresj of the present invention. 5 5 Itmay also be considered asa section taken prefer to providea central transverse web- .on lines.' 1-1 of Figs. 2 and -3 looking in the' direction'of the arrows;

Fig. 2 shows-a cross section taken on line 2--2 of Fig. 1looking in the' direction of the arrows Fig. 3 shows a cross section taken-on line 3 -3 oflFig.'1` looking in the direction of the arrows; and

Fi'g. 1E-Shows Pa fragmentary section on line ,l1-.4 of. Fig. 1 looking in the vdirection of the arrows. I vIn the construction shown in the drawlngs, the engine is intended to drivethe con. nection 6, and the universal joint or other powerv receiving device is intended to be driven by the connection 7 in line therewith. -The connection 6 includes a relatively short stub shaft 8 which is -journalled with respect to the endlwall 9 of the casing by a ball' bearing 10 and `roller bearing 11. vThe driven connection 7 also takes the form of a' relatively short shaft .journalled with re'-4 spect'to the end wall 12 by a roller bearing 13. In the central portion of the machine,

and between the shafts 7 and 8, is locatedl Si" the transmission shaft 14, which vhas itsfront end 15 of reduced size andjournalled within a socket in the Shaftf8 by means of' .a roller bearing 16. The rear end'of the transmission shaft 111 is journalled with re-g spect to the shaft 7 byl a rollerbearing 17.

Mounted on the inner end of the ldriving lshaft 8 isla sprocket 18. Alongside of the transmission shaft 14 is a lay shaft 19, whose ends 20 and 21 are journalled in the heads of the casing by the roller bearings 22 and '23. respectively. 'This lay shaft carries at its forward end a sprocket .24 in line with the sprocket 18, the two sprockets being joined together by a silent chain 25. By this arrangement the lay shaft is constantly driven` by the engine connection- Gand in the same direction as such connection. l

As a matter of rigidity .of construction-I 26 in the'k casing located at approximately the central portlon of the transmission'and vlay. shafts, which shafts may be journalled' with respectl .to tlpeshweb 26 by roller'bear' ings27 and 28, as own. l On .the lay shaft `19 there are 4keyed two sprockets' 29 and 30 of different sizes; and 'on the' transmission shaft 14 in line. with such sprockets there arel .journalled comp1e` mentary sprockets 31 and 32 respectively.

loo'l f sprockets 31 Land 32 are constantly driven 1n the same direction as the engine connection 6, but at different s eeds.

1 0n the rear end of the ay shaft there are keyed-two gears 37 and 38; andon the'rear end of the transmission shaft14 thereis splined a gear 39. A short jack shaft 40 is located at one side of the transmission housing' and carries a pinion 41 vwhich meshes constantly with .the lay shaft gear 37. The

size and position of this pinion 41 are such that whenthe transmission shaft gear 39 is' shifted backward to the first forward drive 39 still further to the rear it passes througlh gear 39' there vis; formed. aclutch element 42 position it meshes with *the pinion 41 but clears the gear 37. Upon shifting the gear the pinion' 41 and directly meshes. with t lay shaft ear 38.

On the ront end ofthe transmission shaft which is normally free of a clutch element 43 .on lthe face of the s rocket 32; but upon -to lock thel another clu [clutch element `is formed Ion the driven moving the gear. 39 orw'ardly` these two clutch-elements are brought together so as sprocket32 and thetransmission shaft 14 together.

On the bk face of th gear 39 isr placed h elementl 44, and a companion shaft 7, the arrangementvbeing such that .when the earr 39 is moved back far enough lio.

. on its rear end a clutch element 47 and on its front end v a'clutch element 48. Companto mesh wlth the layshaft gear 38 thesetwo clutch elements are enmeshedso as to lock the gear n39 to the driven' shaft 7.

' On the front end of the transmission shaft 14 there is s'lidably keyed a lcollar 46 having ion clutch elements 49 and 50 are formed the sprockets 31; and 18 respectively,'so that as the sleeve 46 is'nioved away from the neutral position illustrated'inFig. 1 it` will lock the transmission shaft .either .to the by ,the position of the sleeve. l

A- drivin connectlon is provided .l the -tron shaft '14 and f the 'driven'.Y

shaft 7, so. that, during' the forward rotation of thedrivingf-shaftlfer -the-delive `.of

iare locked'together, but for the delivery of` power ymi lsaid'drivenfslmftj can ru ahead 'of the trans# mission 4, andv comprises a series of of 'the' ange whichv carries the clutch. eleered -ng the different clutch procket 31 or to the sprocket 18, as dictated f A mentns accom 'lishedby the use of ashift.` gives anincreased speedforft the two s afts ase of a tendency. backwards from This. 'oonnectiom' which I- will term a wheel connection, isshown .in detail in Fig. inwardly facing teeth 51 on, the imer face ge `39ywith thepin''on 38. .Simultaneously theY ment 45, together with a series of dogs 52 on' a vplate 53 which is drivingly` connected to the transmission shaft 14. The parts ar'e. so related that the dogs will engage the teeth for forward driving when power is delivfrom the transmission shaft to the driven shaft 7, but the arrangement allows thedriven shaft to run ahead of the trans-` mission shaft when a tendency exists for an opposite-transmission power. This free wheel connection is for the purpose of assisting the driver to move from higher to `lower speed combinations without particular diiiiculty, and while I have illustrated the same in the that a evice of this nature constitutes the particular subject matter of a co-pending aplication for Letters Patent of the United tates, executed by me ofl even date herewith which has matured into lfatent No.

Sultable means may be (provided for shiftevices, particularly thegear 39 andthe collar 46. The means illustrated takes `the form of shifting bars 54 and 55 which extend len hwise of the the other. The bar 54 carries a ork 56 which en a a v or 57 which engages the collar46`.

present, construction"--I wish to statev 80 the gear 39, and-the bar 5 5 carriesj transmission casing, prefera l oneabove `The sequence of movements is as follows:u

In Fig. '1.all of .the ldrivingconnections are' shown--as being disengaged.. The lay shaft' 19 is, however, rotating at -a speed dependent upon the engine speed. The rst or low speed position consists in .shifting the bar 54 rearwardly. so as to mesh the gear 39with the 'jack shaftpinion 41.*?Th1s gives the maximum reduction of speed forward. They next movement consistsin shifting lthe gear 39A together with Aits clutch element 42 forwardly a suiiicient distance tofengage said clutch element with the clutch element 43. o f the sprocket 32. This givesA an increased speed forward. ,l

The next movement `consists in returning the sprocket 39 to the' central'position shown m sprocket 31. 'This-Inova# briny itsclutch 48 into engagement with fthe ing Jthe I clutc l50 of thev sprocket18,whereuponfthe transmission .shaft isY locked directly toil-,hej

driving-shaft 8. 1- As previousl c explained,.the reverse drive 11s accom lishe byAr moving the sprocket 39/ rearwar y, through the first forward drive position andefar venough to engage the ar iao clutch elements 44 and 45 are brought together so that a proper driving connection will be established to thedriven shaft 7 notwithstanding the presence ofthe free wheel attachment illustrated in Fig. 4. i

While I have herein shown anddescribed only a single embodiment ofthe features of my present invention, still I do not limit myself to the same except as I may do so in the claims.

I claim;

1. Ina change speed device, the combination of driving and driven shafts in alignment with each other, having their adjacent ends separated, a transmissionshaft between said adjacentl ends' andjin Ialignment with said shafts, a lay shaft parallel to the transmission shaft, a chain drive connectionfgbetweenthe 'driving shaft and the lay shaft to drive the layshaftin the same direction as the driving shaft, a plurality of -sprockets of different sizes journalled on the .transmission shaft, companion sprockets drivingly mounted on the lay shaft, chain connections between the lay shaft sprockets and the companion .transmission shaft sprockets for continuously driving the latter, a low speed forward drive pinionon the lay shaft adjacent to one of the sprockets thereon, an idler pinion meshing continuously with said lay shaft pinion, another pinion'on the lay shaft of larger size than the first mentioned pinion and further removed from the adjacent lay shaft sprocket than the firstl mentioned pinion, a gear splined on the transmission` shaft and of proper size to engage either the idler pinion or the larger lay shaft pinion selectively, a clutch onsaid gear adapted to engage the driven lshaft when the gear. engages the larger lay shaftpinion, a clutch on the gear adapted to at times engage the adja-` cent transmission shaft sprocket, a sleeve sleeve adapted to engage the driving-shaft when'the sleeve is moved in the other direction, substantially as described.

2; In a change speed device, the combination of a driving'shaft, a transmission shaft in alignment therewith, a lay shaft parallel to the transmission shaft, a sprocket and chain connection-between the driving shaft .and the lay shaft for driving the Vlay shaft 'journalled on the front end of the transi in the same direction as the driving shaft, a

pair lof sprockets of different sizes journalled on the transmission shaft, companion sprockets keyed to the lay shaft, chain drive connections between the lay shaft sprockets and the companion transmission shaft sprockets, a low speed forward drive pinion on the transmission shaft, a reversing pinion on the transmission shaft, further removed from the sprockets thereof than is the first mentioned pinion, an `idler pinion meshing with the' first :mentioned pinion, a gear proper size to engage the idler inion when ls'plined to the. transmission shaft and of moved into one position and o proper size to engage the second mentioned larger p1n" ion on the transmission-shaft when movedl into proper position. a clutch device on said `gear, adapted'to engage the adjacent transmission shaft sprocket when moved into another position, a sleeve on the transmission shaft, a clutch thereon adapted 'to engage the adjacent transmission shaft sprocket when moved into one position, and another clutch thereon adapted to engage the driving vshaft when moved into anotherl position, sub,-

GEORGE stantially as described.

l' J. RACKIIAM. 

